The recent trends of size reduction, weight saving and energy saving of various kinds of devices under concept of downsizing as a key term provide such a tendency that various display devices and thin film solar cells are featured by using a polymer film as substrates thereof. A polymer film is lightweight and is simultaneously rich in flexibility, and thus can suppress various devices from being broken due to cracking. Accordingly, there is an increasing active trend of applying a polymer film to the fields where glass has been employed.
There has been such an attempt that a functional coating layer is formed on an organic material, such as a polymer film, in order to control the refractive index and to suppress gas permeability. However, a transparent conductive laminated body having a transparent conductive layer formed on the coating layer is insufficient in flexural resistance and is difficult to enjoy flexibility of the polymer film sufficiently. In particular, sufficient flexural resistance cannot be obtained in the case where a transparent conductive layer, which provides low resistance, is formed directly on a polymer film. Accordingly, it has been investigated that various organic layers for improving flexural resistance are provided between a polymer film and a transparent conductive film.
A metallic compound layer is often formed on a polymer film for imparting low moisture permeability like glass. However, when the metallic compound layer has such a thickness that is larger than that to provide a continuous layer, although it has a function as a gas barrier layer, the structure of the metallic compound layer might be broken upon receiving an external stress, due to a large difference in elastic modulus between the polymer film and the metallic compound layer, which provides a difference in elongation. Flexibility is considerably decreased when a layer such as a transparent conductive layer having a thickness of about 0.1 μm, is laminated on a metallic compound layer. The loss on flexibility ascribable to the formation of the functional inorganic layer stands in the way of the transparent conductive laminated body using a polymer film, and applications thereof to various devices are inhibited thereby.
In various devices, on the other hand, a transparent conductive layer is often used as an electrode material, known examples of which include ITO containing indium oxide doped with tin, IZO containing indium oxide doped with zinc, GZO containing zinc oxide doped with gallium, and AZO containing zinc oxide doped with aluminum. Adhesiveness of the transparent conductive layers, which are formed on an organic material layer, is demanded to be improved because the transparent conductive layers might be released from the organic material layer due to an external stress for their insufficient adhesiveness. In particular, flexural resistance is becoming an important issue of the transparent conductive laminated body using a polymer film.
Improving the flexural resistance of the transparent conductive laminated body using a polymer film will make the transparent conductive laminated body unlimited in usage. The function that is naturally expected in the transparent conductive laminated body is to use in a device operated in a flexed state. In the purpose of a touch-sensitive panel, in particular, the improvement in flexural resistance of the transparent conductive laminated body can improve the writing resistance of a transparent touch-sensitive panel using the transparent conductive laminated body.
It has been proposed that an undercoating layer is formed immediately under the transparent conductive layer to improve the flexural resistance of the transparent conductive laminated body (as described in Patent Document 1).
In the case where the undercoating layer is an organic material layer, however, it is difficult to ensure the flexural resistance sufficiently in the transparent conductive laminated body having a transparent conductive layer with a low resistance formed on the organic material layer for applications to devices requiring a particularly low resistance.
In order to solve the problem, such a technique for improving the flexural resistance of the transparent conductive laminated body has been developed that a metallic compound layer having relatively high adhesiveness to an organic material is used as the undercoating layer (as described in Patent Document 2). In this case, however, sufficient flexural resistance cannot be obtained with the constitutions shown in Patent Document 2.
The applicant of the present application has disclosed such a technique that inorganic oxide fine particles having an average primary particle diameter of less than 100 nm are segregated at a surface of a cured resin layer for improving the flexural resistance of the transparent conductive laminated body, and has proposed to add a surfactant for segregating the inorganic oxide fine particles at the surface of the cured resin layer (as described in Patent Document 3).
In the case where a surfactant is added, however, it has been confirmed that the surfactant is not fixed within the cured resin layer but is exuded to the surface to cause transfer, which brings about contamination of the transparent conductive laminated body and the like.    [Patent Document 1] JP-A-8-227623    [Patent Document 2] Japanese Patent No. 3146059    [Patent Document 3] JP-A-2004-119188